"Indexing" cases with the head stamp (or other mark made on the case) so that they are placed in the gun and dies in the same orientation every time (within a few degrees of rotation) can make a worthwhile difference in accuracy.

And the more the bolt face is out of square with the chamber axis, the more indexing rounds the same way in the chamber helps.

This is the reason why military rifle teams quit trying to resize fired cases from their service rifles. None of their bolt faces were ever squared up and some were way out of whack. But they shot new cases in factory or handloaded ammo very, very accurate.